Prior to the present invention, there has never existed any satisfactorily-operative multipositioned laterally-spaced sewing machine heads having multiple side-by-side needles thereof reciprocating both in upwardly-downwardly and forwardly-rearwardly directions in synchronization with associated spaced-apart feed-dogs reciprocating forwardly-backwardly directions in essential synchronization where needle and/or feed-dog drive shafts exceeded about sixteen to twenty inches. Because of the complex and involved above-described reciprocable motions of the needles and feed-dogs such a sewing machine, synchronization is essential to avoid the jamming and/or breaking of needles and/or feed-dogs and/or driving mechanism. In the inventor's efforts to enlarge this type machine to a multi-sewing heads machine having a plurality of laterally spaced-apart sewing-heads positions, the synchronization problems were further accentuated and magnified, with much greater stresses and occurances of loss of synchronizations. Upon loss of significant synchronization between the reciprocation of the needles and the feed dogs, in their respective reciprocal movements, stresses rapidly increase to a point at which the drive shaft(s) actually shear-off or break, together with associated jamming or breaking of needle(s) and/or feed-dogs. Even when problems are minor, and/or timely-corrected, the shut-down time is long and costly, as well as operating time between problems being severely limited. Accordingly, it was found that it was impossible to effectively obtain a satisfactorily operable machine utilizing a single-drive chain of force.